In the air gap design of an electric component, the air gap provides a magneto-impedance effect to the electric component for preventing a magnetic saturation phenomenon. At present, the air gap used for the electric components usually comes with a single size. If the air gap of an electric component is too small, then a larger current will pass through the electric component at a low-voltage output condition, and the saturation will occur to produce a significant temperature rise. If the air gap is too large, the electric component will lack of sufficiency for preventing harmonic distortions when the electric component is at a light-load output condition. Therefore, a single size of the air gap cannot satisfy the harmonic wave standard of an electric component under the light-load or full-load condition.
R.O.C. Pat. Publication No. 545686 and U.S. Pat. Publication No. 2004-0178877A1 disclosed the multiple air gap technologies.
In R.O.C. Pat. Publication No. 545686, an electric component forms an air gap with different thicknesses by a paper plate disposed between two cores, so that the curved surface of the air gap is substantially in a stairway-like surface, a slanting surface, or a continuous wavy surface to provide a variable air gap effect as shown in FIG. 1. U.S. Pat. Publication 2004-0178877A1 used a plurality of silicon steel plates having a magnetic flux of different lengths and widths form the cores, such that the air gap with different distances between the two cores will be formed to achieve the variable air gap effect. In the meantime, the effects of reducing the number of coils or stacks of silicon steel plates under the same power condition can be achieved to lower the manufacturing cost and reduce the overall volume of the electric component.
However, the aforementioned two patented technologies cannot achieve the accurate control effect primarily because the curved surface or different distances of the air gap cannot be used to calculate the actual light-load or full-load power accurately, and the manufacture of the electric component involves different specifications due to the factors of human assembling or the errors of manufacturing tools. If there is a new specification, the existing specification for the electric components cannot be used anymore, and it is necessary to perform experiments repeatedly to find an appropriate air gap, and the process is very laborious.